/Engine/Source/Runtime/Engine/Classes/GameFramework/Actor.h
https://www.unrealengine.com/blog/damage-in-ue4
virtual float TakeDamage ( float DamageAmount, struct [FDamageEvent](API\Runtime\Engine\Engine\FDamageEvent) const & DamageEvent, class [AController](API\Runtime\Engine\GameFramework\AController) * EventInstigator, [AActor](API\Runtime\Engine\GameFramework\AActor) * DamageCauser )